VEGFA and choroidal neovascularization: Although serum concentrations of conbercept become undetectable within 1-2 days after intravitreal injection during phase I trial, serum obtained from patients with choroidal neovascularization or polypoidal choroidal vasculopathy during the follow-up period after intravitreal injection of conbercept revealed that serum concentrations of VEGF significantly reduced, lasted for 1 week, and regressed at 1 month [12].